Develop Reference

CSS attribute not always being grabbed by javascript correctly

I am trying to resize the side bars whenever the image changes.
I have my javascript trying grab the height of the image after it changes
var imgHeight = $('#mainImg').height();
var currImg = 0;
var imagesSet = ["1.jpg", "2.jpg", "3.jpg", "4.jpg", "5.jpg", "6.jpg"];
var imageLoc = "images/zalman/"
$('#bttnRight').click(function(){
nextImg();
imgHeight = $('#mainImg').height();
resizeBttn();
});
function nextImg(){
currImg++;
if(currImg>=imagesSet.length){
currImg=0;
}
$('#mainImg').attr("src",imageLoc + imagesSet[currImg]);
}
function resizeBttn() {
$(document).ready(function() {
$('#bttnLeft').css("height",imgHeight);
$('#bttnLeft').css("bottom",imgHeight/2-5);
});
$(document).ready(function() {
$('#bttnRight').css("height",imgHeight);
$('#bttnRight').css("bottom",imgHeight/2-5);
});
}
for some reason, it doesn't always grab the height at the correct time and the side bars will stay at the previous height.
Below I have a JSFiddle that should be working the way my setup is.
Please excuse any inconsistencies and inefficiencies, I am learning.
Just seems weird that it would sometimes grab the height and sometimes not.
I will also be attaching an image of what I see sometimes from the JSfiddle.
I will also attach an image of what I see on my site I am actually writing.
https://jsfiddle.net/6bewkuo5/6/

The issue is because your JavaScript accessing the height of the image before the image as actually been re-rendered in the DOM. Adding a slight delay after assigning the new image source may help things, but...
You actually don't need to use JavaScript to set the height of the buttons
You can achieve what you're after by placing the buttons and image inside of a container with css attribute display: flex.
Like this:
.container {
display: flex;
justify-content: center;
}
<div class="container">
<button class="prev"><</button>
<img src="https://www.avalonwinery.com/wp-content/uploads/2013/12/200x300.gif">
<button class="next">></button>
</div>
Elements within a flex container will automatically fill the height, this includes buttons. Because the images will automatically adjust the height of the container, the buttons will also automatically adjust their height to match.
Run the example below
const images = [
"https://www.avalonwinery.com/wp-content/uploads/2013/12/200x300.gif",
"https://images.sftcdn.net/images/t_app-logo-xl,f_auto/p/ce2ece60-9b32-11e6-95ab-00163ed833e7/1578981868/the-test-fun-for-friends-logo.png",
"https://hiveconnect.co.za/wp-content/uploads/2018/05/800x600.png",
"https://upload.wikimedia.org/wikipedia/commons/b/b5/800x600_Wallpaper_Blue_Sky.png"
]
const imageEl = document.querySelector('img')
let imageIndex = 0
document.querySelector('.prev').addEventListener('click', e => {
if (--imageIndex < 0) { imageIndex = images.length - 1 }
imageEl.src = images[imageIndex]
})
document.querySelector('.next').addEventListener('click', e => {
if (++imageIndex > images.length - 1) { imageIndex = 0 }
imageEl.src = images[imageIndex]
})
body {
background-color: #206a5d;
color: #ffffff;
text-align: center;
}
.container {
display: flex;
justify-content: center;
}
img {
max-width: 50%;
}
<h1>Zalman Build</h1>
<div class="container">
<button class="prev"><</button>
<img src="https://www.avalonwinery.com/wp-content/uploads/2013/12/200x300.gif">
<button class="next">></button>
</div>

The reason is because the resizeBttn code is firing before the image has actually finished downloading and loading into the DOM. I made these changes in your fiddle:
var imgHeight = $('#mainImg').height();
var currImg = 0;
var imagesSet = ["https://www.avalonwinery.com/wp-content/uploads/2013/12/200x300.gif","https://images.sftcdn.net/images/t_app-logo-xl,f_auto/p/ce2ece60-9b32-11e6-95ab-00163ed833e7/1578981868/the-test-fun-for-friends-logo.png", "https://hiveconnect.co.za/wp-content/uploads/2018/05/800x600.png", "https://upload.wikimedia.org/wikipedia/commons/b/b5/800x600_Wallpaper_Blue_Sky.png"];
var imageLoc = "images/zalman/"
$(document).ready(function() {
resizeBttn();
});
$( window ).resize(function() {
/* imgHeight = $('#mainImg').height() */; // commented out; we do this in resizeBttn now
resizeBttn();
});
$('#bttnLeft').click(function(){
prevImg();
/* imgHeight = $('#mainImg').height() */; // commented out; we do this in resizeBttn now
/* resizeBttn() */; // we do this as an `onload` to the image now
});
$('#bttnRight').click(function(){
nextImg();
/* imgHeight = $('#mainImg').height() */; // commented out; we do this in resizeBttn now
/* resizeBttn() */; // we do this as an `onload` to the image now
});
function nextImg(){
currImg++;
if(currImg>=imagesSet.length){
currImg=0;
}
$('#mainImg').attr("src",imagesSet[currImg]);
}
function prevImg(){
currImg--;
if(currImg<0){
currImg=imagesSet.length-1;
}
$('#mainImg').attr("src",imagesSet[currImg]);
}
function resizeBttn() {
imgHeight = $('#mainImg').height()
// removed superfluous doc.ready
$('#bttnLeft').css("height",imgHeight);
$('#bttnLeft').css("bottom",imgHeight/2-5);
$('#bttnRight').css("height",imgHeight);
$('#bttnRight').css("bottom",imgHeight/2-5);
}
And then rewrote your <img /> tag to call resizeBttn on onload:
<img id="mainImg" src="https://www.avalonwinery.com/wp-content/uploads/2013/12/200x300.gif" onload="resizeBttn()"/>
You can see this in action in this fiddle.
Also, a few additional notes on your code, at a glance:
You have some invalid HTML; you're going to want to run that through an HTML validator and fix it, because sometimes it is fine, but sometimes it can lead to all sorts of strange behavior.
You're playing fast and l0ose with global variables in your JS that get set in different functions; it might work OK while the script is small, but as things scale it can quickly become difficult to maintain
You should really avoid abusing the onclick to get link-like behavior from <li> elements; it can impact SEO as well as accessibility. I'd recommend simply using an anchor element inside or outside the <li>
I'd recommend taking a close look at this answer by user camaulay; he makes an excellent point that this may not require JS at all- if a more elegant solution exists w/ CSS it is probably going to be more performant and maintainable.

How to trigger event in JS when reaching the bottom of the page in cases where there's no scroll

I have an event listener for scrolling to the bottom of the page that works fine:
document.addEventListener('scroll', () => {
if (window.innerHeight + window.pageYOffset >= document.body.offsetHeight) {
console.log("bottom reached");
}
});
BUT my issue is that if the page loads and the document is shorter than the window, this won't trigger because there's no scroll event. The document fits in the window, in other words, so no need to scroll to the bottom.
I still want to trigger something in this case, though. How do I do that?
I thought about just having a conditional statement within a DOMContentLoaded event listener that checks if the window is bigger than the document, i.e.
if (window.innerHeight + window.pageYOffset >= document.body.offsetHeight) {
console.log("window size exceeds page size");
}
While this works, it gives me a "forced reflow" performance violation warning in the console, basically saying this is taking too long.
Any advice on how to handle this?

Your solution is the simplest and if you do not have any other problems with it rather than the warning in the console, it might be the best.
Another way would be to use the Intersection Observer API, which is executed on load.
Here is a simple example:
<head>
<style>
.container {
width: 100%;
height: 80%;
background-color: whitesmoke;
}
</style>
</head>
<body>
<div class="container"></div>
<script>
const container = document.querySelector('.container')
const observer = new IntersectionObserver(callback, {
root: null, // intersect with viewport
rootMargin: '0px', // no margin when computing intersections
threshold: 1.0, // execute callback when every pixel is visible
})
function callback(entries) {
for (const entry of entries) {
if (entry.isIntersecting) {
console.log("i am also fired on load")
}
}
}
observer.observe(container)
</script>
</body>
You could also observe your footer or some element at the bottom of the page. Using Intersection Observer you do not even have to use the scroll event listener.

How do I scroll to an element which is present inside an overflow div which itself is inside an an overflow container? [duplicate]

I am creating a chat using Ajax requests and I'm trying to get messages div to scroll to the bottom without much luck.
I am wrapping everything in this div:
#scroll {
height:400px;
overflow:scroll;
}
Is there a way to keep it scrolled to the bottom by default using JS?
Is there a way to keep it scrolled to the bottom after an ajax request?

Here's what I use on my site:
var objDiv = document.getElementById("your_div");
objDiv.scrollTop = objDiv.scrollHeight;

This is much easier if you're using jQuery scrollTop:
$("#mydiv").scrollTop($("#mydiv")[0].scrollHeight);

Try the code below:
const scrollToBottom = (id) => {
const element = document.getElementById(id);
element.scrollTop = element.scrollHeight;
}
You can also use Jquery to make the scroll smooth:
const scrollSmoothlyToBottom = (id) => {
const element = $(`#${id}`);
element.animate({
scrollTop: element.prop("scrollHeight")
}, 500);
}
Here is the demo
Here's how it works:
Ref: scrollTop, scrollHeight, clientHeight

using jQuery animate:
$('#DebugContainer').stop().animate({
scrollTop: $('#DebugContainer')[0].scrollHeight
}, 800);

Newer method that works on all current browsers:
this.scrollIntoView(false);

var mydiv = $("#scroll");
mydiv.scrollTop(mydiv.prop("scrollHeight"));
Works from jQuery 1.6
https://api.jquery.com/scrollTop/
http://api.jquery.com/prop/

alternative solution
function scrollToBottom(element) {
element.scroll({ top: element.scrollHeight, behavior: 'smooth' });
}

smooth scroll with Javascript:
document.getElementById('messages').scrollIntoView({ behavior: 'smooth', block: 'end' });

If you don't want to rely on scrollHeight, the following code helps:
$('#scroll').scrollTop(1000000);

Java Script:
document.getElementById('messages').scrollIntoView(false);
Scrolls to the last line of the content present.

My Scenario: I had an list of string, in which I had to append a string given by a user and scroll to the end of the list automatically. I had fixed height of the display of the list, after which it should overflow.
I tried #Jeremy Ruten's answer, it worked, but it was scrolling to the (n-1)th element. If anybody is facing this type of issue, you can use setTimeOut() method workaround. You need to modify the code to below:
setTimeout(() => {
var objDiv = document.getElementById('div_id');
objDiv.scrollTop = objDiv.scrollHeight
}, 0)
Here is the StcakBlitz link I have created which shows the problem and its solution : https://stackblitz.com/edit/angular-ivy-x9esw8

If your project targets modern browsers, you can now use CSS Scroll Snap to control the scrolling behavior, such as keeping any dynamically generated element at the bottom.
.wrapper > div {
background-color: white;
border-radius: 5px;
padding: 5px 10px;
text-align: center;
font-family: system-ui, sans-serif;
}
.wrapper {
display: flex;
padding: 5px;
background-color: #ccc;
border-radius: 5px;
flex-direction: column;
gap: 5px;
margin: 10px;
max-height: 150px;
/* Control snap from here */
overflow-y: auto;
overscroll-behavior-y: contain;
scroll-snap-type: y mandatory;
}
.wrapper > div:last-child {
scroll-snap-align: start;
}
<div class="wrapper">
<div>01</div>
<div>02</div>
<div>03</div>
<div>04</div>
<div>05</div>
<div>06</div>
<div>07</div>
<div>08</div>
<div>09</div>
<div>10</div>
</div>

You can use the HTML DOM scrollIntoView Method like this:
var element = document.getElementById("scroll");
element.scrollIntoView();

Javascript or jquery:
var scroll = document.getElementById('messages');
scroll.scrollTop = scroll.scrollHeight;
scroll.animate({scrollTop: scroll.scrollHeight});
Css:
.messages
{
height: 100%;
overflow: auto;
}

Using jQuery, scrollTop is used to set the vertical position of scollbar for any given element. there is also a nice jquery scrollTo plugin used to scroll with animation and different options (demos)
var myDiv = $("#div_id").get(0);
myDiv.scrollTop = myDiv.scrollHeight;
if you want to use jQuery's animate method to add animation while scrolling down, check the following snippet:
var myDiv = $("#div_id").get(0);
myDiv.animate({
scrollTop: myDiv.scrollHeight
}, 500);

I have encountered the same problem, but with an additional constraint: I had no control over the code that appended new elements to the scroll container. None of the examples I found here allowed me to do just that. Here is the solution I ended up with .
It uses Mutation Observers (https://developer.mozilla.org/en-US/docs/Web/API/MutationObserver) which makes it usable only on modern browsers (though polyfills exist)
So basically the code does just that :
var scrollContainer = document.getElementById("myId");
// Define the Mutation Observer
var observer = new MutationObserver(function(mutations) {
// Compute sum of the heights of added Nodes
var newNodesHeight = mutations.reduce(function(sum, mutation) {
return sum + [].slice.call(mutation.addedNodes)
.map(function (node) { return node.scrollHeight || 0; })
.reduce(function(sum, height) {return sum + height});
}, 0);
// Scroll to bottom if it was already scrolled to bottom
if (scrollContainer.clientHeight + scrollContainer.scrollTop + newNodesHeight + 10 >= scrollContainer.scrollHeight) {
scrollContainer.scrollTop = scrollContainer.scrollHeight;
}
});
// Observe the DOM Element
observer.observe(scrollContainer, {childList: true});
I made a fiddle to demonstrate the concept :
https://jsfiddle.net/j17r4bnk/

Found this really helpful, thank you.
For the Angular 1.X folks out there:
angular.module('myApp').controller('myController', ['$scope', '$document',
function($scope, $document) {
var overflowScrollElement = $document[0].getElementById('your_overflow_scroll_div');
overflowScrollElement[0].scrollTop = overflowScrollElement[0].scrollHeight;
}
]);
Just because the wrapping in jQuery elements versus HTML DOM elements gets a little confusing with angular.
Also for a chat application, I found making this assignment after your chats were loaded to be useful, you also might need to slap on short timeout as well.

Like you, I'm building a chat app and want the most recent message to scroll into view. This ultimately worked well for me:
//get the div that contains all the messages
let div = document.getElementById('message-container');
//make the last element (a message) to scroll into view, smoothly!
div.lastElementChild.scrollIntoView({ behavior: 'smooth' });

small addendum: scrolls only, if last line is already visible. if scrolled a tiny bit, leaves the content where it is (attention: not tested with different font sizes. this may need some adjustments inside ">= comparison"):
var objDiv = document.getElementById(id);
var doScroll=objDiv.scrollTop>=(objDiv.scrollHeight-objDiv.clientHeight);
// add new content to div
$('#' + id ).append("new line at end<br>"); // this is jquery!
// doScroll is true, if we the bottom line is already visible
if( doScroll) objDiv.scrollTop = objDiv.scrollHeight;

Just as a bonus snippet. I'm using angular and was trying to scroll a message thread to the bottom when a user selected different conversations with users. In order to make sure that the scroll works after the new data had been loaded into the div with the ng-repeat for messages, just wrap the scroll snippet in a timeout.
$timeout(function(){
var messageThread = document.getElementById('message-thread-div-id');
messageThread.scrollTop = messageThread.scrollHeight;
},0)
That will make sure that the scroll event is fired after the data has been inserted into the DOM.

This will let you scroll all the way down regards the document height
$('html, body').animate({scrollTop:$(document).height()}, 1000);

You can also, using jQuery, attach an animation to html,body of the document via:
$("html,body").animate({scrollTop:$("#div-id")[0].offsetTop}, 1000);
which will result in a smooth scroll to the top of the div with id "div-id".

Scroll to the last element inside the div:
myDiv.scrollTop = myDiv.lastChild.offsetTop

You can use the Element.scrollTo() method.
It can be animated using the built-in browser/OS animation, so it's super smooth.
function scrollToBottom() {
const scrollContainer = document.getElementById('container');
scrollContainer.scrollTo({
top: scrollContainer.scrollHeight,
left: 0,
behavior: 'smooth'
});
}
// initialize dummy content
const scrollContainer = document.getElementById('container');
const numCards = 100;
let contentInnerHtml = '';
for (let i=0; i<numCards; i++) {
contentInnerHtml += `<div class="card mb-2"><div class="card-body">Card ${i + 1}</div></div>`;
}
scrollContainer.innerHTML = contentInnerHtml;
.overflow-y-scroll {
overflow-y: scroll;
}
<link href="https://cdn.jsdelivr.net/npm/bootstrap#4.5.3/dist/css/bootstrap.min.css" rel="stylesheet"/>
<div class="d-flex flex-column vh-100">
<div id="container" class="overflow-y-scroll flex-grow-1"></div>
<div>
<button class="btn btn-primary" onclick="scrollToBottom()">Scroll to bottom</button>
</div>
</div>

Css only:
.scroll-container {
overflow-anchor: none;
}
Makes it so the scroll bar doesn't stay anchored to the top when a child element is added. For example, when new message is added at the bottom of chat, scroll chat to new message.

Why not use simple CSS to do this?
The trick is to use display: flex; and flex-direction: column-reverse;
Here is a working example. https://codepen.io/jimbol/pen/YVJzBg

A very simple method to this is to set the scroll to to the height of the div.
var myDiv = document.getElementById("myDiv");
window.scrollTo(0, myDiv.innerHeight);

On my Angular 6 application I just did this:
postMessage() {
// post functions here
let history = document.getElementById('history')
let interval
interval = setInterval(function() {
history.scrollTop = history.scrollHeight
clearInterval(interval)
}, 1)
}
The clearInterval(interval) function will stop the timer to allow manual scroll top / bottom.

I know this is an old question, but none of these solutions worked out for me. I ended up using offset().top to get the desired results. Here's what I used to gently scroll the screen down to the last message in my chat application:
$("#html, body").stop().animate({
scrollTop: $("#last-message").offset().top
}, 2000);
I hope this helps someone else.

I use the difference between the Y coordinate of the first item div and the Y coordinate of the selected item div. Here is the JavaScript/JQuery code and the html:
function scrollTo(event){
// In my proof of concept, I had a few <button>s with value
// attributes containing strings with id selector expressions
// like "#item1".
let selectItem = $($(event.target).attr('value'));
let selectedDivTop = selectItem.offset().top;
let scrollingDiv = selectItem.parent();
let firstItem = scrollingDiv.children('div').first();
let firstItemTop = firstItem.offset().top;
let newScrollValue = selectedDivTop - firstItemTop;
scrollingDiv.scrollTop(newScrollValue);
}
<div id="scrolling" style="height: 2rem; overflow-y: scroll">
<div id="item1">One</div>
<div id="item2">Two</div>
<div id="item3">Three</div>
<div id="item4">Four</div>
<div id="item5">Five</div>
</div>

Resize on div element

jQuery has the resize() - event, but it just work with window.
jQuery(window).resize(function() { /* What ever */ });
This works fine! But when I want to add the event to a div element it doesn't work.
E.g.
jQuery('div').resize(function() { /* What ever */ });
I want to start an callback when the size of a div-element has changed. I don't want to start a resizable - event – just a event to check if the size of a div -
element has changed.
Is there any solution to do this?

DIV does not fire a resize event, so you won't be able to do exactly what you've coded, but you could look into monitoring DOM properties.
If you are actually working with something like resizables, and that is the only way for a div to change in size, then your resize plugin will probably be implementing a callback of its own.

I was only interested for a trigger when a width of an element was changed (I don' care about height), so I created a jquery event that does exactly that, using an invisible iframe element.
$.event.special.widthChanged = {
remove: function() {
$(this).children('iframe.width-changed').remove();
},
add: function () {
var elm = $(this);
var iframe = elm.children('iframe.width-changed');
if (!iframe.length) {
iframe = $('<iframe/>').addClass('width-changed').prependTo(this);
}
var oldWidth = elm.width();
function elmResized() {
var width = elm.width();
if (oldWidth != width) {
elm.trigger('widthChanged', [width, oldWidth]);
oldWidth = width;
}
}
var timer = 0;
var ielm = iframe[0];
(ielm.contentWindow || ielm).onresize = function() {
clearTimeout(timer);
timer = setTimeout(elmResized, 20);
};
}
}
It requires the following css :
iframe.width-changed {
width: 100%;
display: block;
border: 0;
height: 0;
margin: 0;
}
You can see it in action here widthChanged fiddle

// this is a Jquery plugin function that fires an event when the size of an element is changed
// usage: $().sizeChanged(function(){})
(function ($) {
$.fn.sizeChanged = function (handleFunction) {
var element = this;
var lastWidth = element.width();
var lastHeight = element.height();
setInterval(function () {
if (lastWidth === element.width()&&lastHeight === element.height())
return;
if (typeof (handleFunction) == 'function') {
handleFunction({ width: lastWidth, height: lastHeight },
{ width: element.width(), height: element.height() });
lastWidth = element.width();
lastHeight = element.height();
}
}, 100);
return element;
};
}(jQuery));

I've created jquery plugin jquery.resize it use resizeObserver if supported or solution based on marcj/css-element-queries scroll event, no setTimeout/setInterval.
You use just
jQuery('div').on('resize', function() { /* What ever */ });
or as resizer plugin
jQuery('div').resizer(function() { /* What ever */ });
I've created this for jQuery Terminal and extracted into separated repo and npm package, but in a mean time I switched to hidden iframe because I had problems with resize if element was inside iframe. I may update the plugin accordingly. You can look at iframe based resizer plugin in jQuery Terminal source code.
EDIT: new version use iframe and resize on it's window object because the previous solutions was not working when page was inside iframe.
EDIT2: Because the fallback use iframe you can't use it with form controls or images, you need to add it to the wrapper element.
EDIT3:: there is better solution using resizeObserver polyfill that use mutation observer (if resizeObserver is not supported) and work even in IE. It also have TypeScript typings.

what about this:
divH = divW = 0;
jQuery(document).ready(function(){
divW = jQuery("div").width();
divH = jQuery("div").height();
});
function checkResize(){
var w = jQuery("div").width();
var h = jQuery("div").height();
if (w != divW || h != divH) {
/*what ever*/
divH = h;
divW = w;
}
}
jQuery(window).resize(checkResize);
var timer = setInterval(checkResize, 1000);
BTW I suggest you to add an id to the div and change the $("div") to $("#yourid"), it's gonna be faster, and it won't break when later you add other divs

There is a really nice, easy to use, lightweight (uses native browser events for detection) plugin for both basic JavaScript and for jQuery that was released this year. It performs perfectly:
https://github.com/sdecima/javascript-detect-element-resize

Only window is supported yes but you could use a plugin for it: http://benalman.com/projects/jquery-resize-plugin/

There now exists Resize Observer
You could use it like so:
const resizeObserver = new ResizeObserver((entries) => {
entries.forEach(console.log);
})
resizeObserver.observe(document.getElementById("ExampleElement"));

For a google maps integration I was looking for a way to detect when a div has changed in size. Since google maps always require proper dimensions e.g. width and height in order to render properly.
The solution I came up with is a delegation of an event, in my case a tab click. This could be a window resize of course, the idea remains the same:
if (parent.is(':visible')) {
w = parent.outerWidth(false);
h = w * mapRatio /*9/16*/;
this.map.css({ width: w, height: h });
} else {
this.map.closest('.tab').one('click', function() {
this.activate();
}.bind(this));
}
this.map in this case is my map div.
Since my parent is invisible on load, the computed width and height are 0 or don't match.
By using .bind(this) I can delegate the script execution (this.activate) to an event (click).
Now I'm confident the same applies for resize events.
$(window).one('resize', function() {
this.div.css({ /*whatever*/ });
}.bind(this));
Hope it helps anyone!

You can change your text or Content or Attribute depend on Screen size:
HTML:
<p class="change">Frequently Asked Questions (FAQ)</p>
<p class="change">Frequently Asked Questions </p>
Javascript:
<script>
const changeText = document.querySelector('.change');
function resize() {
if((window.innerWidth<500)&&(changeText.textContent="Frequently Asked Questions (FAQ)")){
changeText.textContent="FAQ";
} else {
changeText.textContent="Frequently Asked Questions (FAQ)";
}
}
window.onresize = resize;
</script>

document.addEventListener('transitionend', function(e) {
if ($(e.target).is("div")) {
$("div").text("width: "+$("div").width());
}
});
$("div").css({"width":"150px"});
<script src="https://cdnjs.cloudflare.com/ajax/libs/jquery/3.3.1/jquery.min.js"></script>
<div style="width: 100px;transition-delay: 0.000000001s;">width: 100</div>

A very simple implementation.
<script>
var move = function(e) {
if ((e.w && e.w !== e.offsetWidth) || (e.h && e.h !== e.offsetHeight)) {
new Function(e.getAttribute('onresize')).call(e);
}
e.w = e.offsetWidth;
e.h = e.offsetHeight;
}
var resize = function() {
console.log('Resized')
}
</script>
<style>
.resizable {
resize: both;
overflow: auto;
width: 200px;
border: 1px solid black;
padding: 20px;
}
</style>
<div class='resizable' onresize="resize(this)" onmousemove="move(this)">
Pure vanilla implementation
</div>

If you just want to resize the div itself you need to specify that in css style. You need to add overflow and resize property.
Below is my code snippet
#div1 {
width: 90%;
height: 350px;
padding: 10px;
border: 1px solid #aaaaaa;
overflow: auto;
resize: both;
}
<div id="div1">
</div>

Wait cursor over entire html page

Is it possible to set the cursor to 'wait' on the entire html page in a simple way? The idea is to show the user that something is going on while an ajax call is being completed. The code below shows a simplified version of what I tried and also demonstrate the problems I run into:
if an element (#id1) has a cursor style set it will ignore the one set on body (obviously)
some elements have a default cursor style (a) and will not show the wait cursor on hover
the body element has a certain height depending on the content and if the page is short, the cursor will not show below the footer
The test:
<html>
<head>
<style type="text/css">
#id1 {
background-color: #06f;
cursor: pointer;
}
#id2 {
background-color: #f60;
}
</style>
</head>
<body>
<div id="id1">cursor: pointer</div>
<div id="id2">no cursor</div>
Do something
</body>
</html>
Later edit...
It worked in firefox and IE with:
div#mask { display: none; cursor: wait; z-index: 9999;
position: absolute; top: 0; left: 0; height: 100%;
width: 100%; background-color: #fff; opacity: 0; filter: alpha(opacity = 0);}
<a href="#" onclick="document.getElementById('mask').style.display = 'block'; return false">
Do something</a>
The problem with (or feature of) this solution is that it will prevent clicks because of the overlapping div (thanks Kibbee)
Later later edit...
A simpler solution from Dorward:
.wait, .wait * { cursor: wait !important; }
and then
Do something
This solution only shows the wait cursor but allows clicks.

If you use this slightly modified version of the CSS you posted from Dorward,
html.wait, html.wait * { cursor: wait !important; }
you can then add some really simple jQuery to work for all ajax calls:
$(document).ready(function () {
$(document).ajaxStart(function () { $("html").addClass("wait"); });
$(document).ajaxStop(function () { $("html").removeClass("wait"); });
});
or, for older jQuery versions (before 1.9):
$(document).ready(function () {
$("html").ajaxStart(function () { $(this).addClass("wait"); });
$("html").ajaxStop(function () { $(this).removeClass("wait"); });
});

I understand you may not have control over this, but you might instead go for a "masking" div that covers the entire body with a z-index higher than 1. The center part of the div could contain a loading message if you like.
Then, you can set the cursor to wait on the div and don't have to worry about links as they are "under" your masking div. Here's some example CSS for the "masking div":
body { height: 100%; }
div#mask { cursor: wait; z-index: 999; height: 100%; width: 100%; }

This seems to work in firefox
<style>
*{ cursor: inherit;}
body{ cursor: wait;}
</style>
The * part ensures that the cursor doesn't change when you hover over a link. Although links will still be clickable.

I have been struggling with this problem for hours today.
Basically everything was working just fine in FireFox but (of course) not in IE.
In IE the wait cursor was showing AFTER the time consuming function was executed.
I finally found the trick on this site:
http://www.codingforums.com/archive/index.php/t-37185.html
Code:
//...
document.body.style.cursor = 'wait';
setTimeout(this.SomeLongFunction, 1);
//setTimeout syntax when calling a function with parameters
//setTimeout(function() {MyClass.SomeLongFunction(someParam);}, 1);
//no () after function name this is a function ref not a function call
setTimeout(this.SetDefaultCursor, 1);
...
function SetDefaultCursor() {document.body.style.cursor = 'default';}
function SomeLongFunction(someParam) {...}
My code runs in a JavaScript class hence the this and MyClass (MyClass is a singleton).
I had the same problems when trying to display a div as described on this page. In IE it was showing after the function had been executed. So I guess this trick would solve that problem too.
Thanks a zillion time to glenngv the author of the post. You really made my day!!!

Easiest way I know is using JQuery like this:
$('*').css('cursor','wait');

css: .waiting * { cursor: 'wait' }
jQuery: $('body').toggleClass('waiting');

Why don't you just use one of those fancy loading graphics (eg: http://ajaxload.info/)? The waiting cursor is for the browser itself - so whenever it appears it has something to do with the browser and not with the page.

To set the cursor from JavaScript for the whole window, use:
document.documentElement.style.cursor = 'wait';
From CSS:
html { cursor: wait; }
Add further logic as needed.

Try the css:
html.waiting {
cursor: wait;
}
It seems that if the property body is used as apposed to html it doesn't show the wait cursor over the whole page. Furthermore if you use a css class you can easily control when it actually shows it.

Here is a more elaborate solution that does not require external CSS:
function changeCursor(elem, cursor, decendents) {
if (!elem) elem=$('body');
// remove all classes starting with changeCursor-
elem.removeClass (function (index, css) {
return (css.match (/(^|\s)changeCursor-\S+/g) || []).join(' ');
});
if (!cursor) return;
if (typeof decendents==='undefined' || decendents===null) decendents=true;
let cname;
if (decendents) {
cname='changeCursor-Dec-'+cursor;
if ($('style:contains("'+cname+'")').length < 1) $('<style>').text('.'+cname+' , .'+cname+' * { cursor: '+cursor+' !important; }').appendTo('head');
} else {
cname='changeCursor-'+cursor;
if ($('style:contains("'+cname+'")').length < 1) $('<style>').text('.'+cname+' { cursor: '+cursor+' !important; }').appendTo('head');
}
elem.addClass(cname);
}
with this you can do:
changeCursor(, 'wait'); // wait cursor on all decendents of body
changeCursor($('#id'), 'wait', false); // wait cursor on elem with id only
changeCursor(); // remove changed cursor from body

I used a adaptation of Eric Wendelin's solution. It will show a transparent, animated overlay wait-div over the whole body, the click will be blocked by the wait-div while visible:
css:
div#waitMask {
z-index: 999;
position: absolute;
top: 0;
right: 0;
height: 100%;
width: 100%;
cursor: wait;
background-color: #000;
opacity: 0;
transition-duration: 0.5s;
-webkit-transition-duration: 0.5s;
}
js:
// to show it
$("#waitMask").show();
$("#waitMask").css("opacity"); // must read it first
$("#waitMask").css("opacity", "0.8");
...
// to hide it
$("#waitMask").css("opacity", "0");
setTimeout(function() {
$("#waitMask").hide();
}, 500) // wait for animation to end
html:
<body>
<div id="waitMask" style="display:none;"> </div>
... rest of html ...

My Two pence:
Step 1:
Declare an array. This will be used to store the original cursors that were assigned:
var vArrOriginalCursors = new Array(2);
Step 2:
Implement the function cursorModifyEntirePage
function CursorModifyEntirePage(CursorType){
var elements = document.body.getElementsByTagName('*');
alert("These are the elements found:" + elements.length);
let lclCntr = 0;
vArrOriginalCursors.length = elements.length;
for(lclCntr = 0; lclCntr < elements.length; lclCntr++){
vArrOriginalCursors[lclCntr] = elements[lclCntr].style.cursor;
elements[lclCntr].style.cursor = CursorType;
}
}
What it does:
Gets all the elements on the page. Stores the original cursors assigned to them in the array declared in step 1. Modifies the cursors to the desired cursor as passed by parameter CursorType
Step 3:
Restore the cursors on the page
function CursorRestoreEntirePage(){
let lclCntr = 0;
var elements = document.body.getElementsByTagName('*');
for(lclCntr = 0; lclCntr < elements.length; lclCntr++){
elements[lclCntr].style.cursor = vArrOriginalCursors[lclCntr];
}
}
I have run this in an application and it works fine.
Only caveat is that I have not tested it when you are dynamically adding the elements.

BlockUI is the answer for everything. Give it a try.
http://www.malsup.com/jquery/block/

This pure JavaScript seems to work pretty well ... tested on FireFox, Chrome, and Edge browsers.
I'm not sure about the performance of this if you had an overabundance of elements on your page and a slow computer ... try it and see.
Set cursor for all elements to wait:
Object.values(document.querySelectorAll('*')).forEach(element => element.style.cursor = "wait");
Set cursor for all elements back to default:
Object.values(document.querySelectorAll('*')).forEach(element => element.style.cursor = "default");
An alternative (and perhaps a bit more readable) version would be to create a setCursor function as follows:
function setCursor(cursor)
{
var x = document.querySelectorAll("*");
for (var i = 0; i < x.length; i++)
{
x[i].style.cursor = cursor;
}
}
and then call
setCursor("wait");
and
setCursor("default");
to set the wait cursor and default cursor respectively.

Lots of good answers already, but none of them mentions the <dialog> element.
Using this element we can create a solution similar to the masking <div>.
Here we use showModal() to "hide" elements, and we use ::backdrop to set the cursor style to wait on the entire page:
function showWaitDialog() {
document.getElementById('id_dialog').showModal();
}
#id_dialog, #id_dialog::backdrop {
cursor: wait;
}
<button onclick="showWaitDialog()">click me</button>
<dialog id="id_dialog">busy...</dialog>
The dialog is hidden by default, and can be shown using either the show() method, or the showModal() method, which prevents clicking outside the dialog.
The dialog can be forced to close using the close() method, if necessary.
However, if your button links to another page, for example, then the dialog will disappear automatically as soon as the new page is loaded.
Note that the dialog can also be closed at any time by hitting the Esc key.
CSS can be used to style the dialog however you like.
The example uses the html onclick attribute, just for simplicity. Obviously, addEventListener() could also be used.

Late to the party but simply give the Html tag an id by targeting
document.documentElement
and in the CSS place at the top
html#wait * {
cursor: wait !important;
}
and simply remove it when you want to stop this cursor.